HD64F3028F25 Datasheet, PDF (631/925 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

18.6 Flash Memory Programming/Erasing
A software method, using the CPU, is employed to program and erase flash memory in the on-
board programming modes. There are four flash memory operating modes: program mode, erase
mode, program-verify mode, and erase-verify mode. Transitions to these modes for addresses
H'000000 to H'03FFFF are made by setting the PSU, ESU, P, E, PV, and EV bits in FLMCR1.
The flash memory cannot be read while being programmed or erased. Therefore, the program
(user program) that controls flash memory programming/erasing should be located and executed in
on-chip RAM or external memory.
See section 18.11, Flash Memory Programming and Erasing Precautions, for points to be noted
when programming or erasing the flash memory. In the following operation descriptions, wait
times after setting or clearing individual bits in FLMCR1 are given as parameters; for details of
the wait times, see section 21.2.6, Flash Memory Characteristics.
Notes: 1. Operation is not guaranteed if setting/resetting of the SWE, ESU, PSU, EV, PV, E, and
P bits in FLMCR1 is executed by a program in flash memory.
2. When programming or erasing, set FWE to 1 (programming/erasing will not be
executed if FWE = 0).
3. Programming must be executed in the erased state. Do not perform additional
programming on addresses that have already been programmed.
Rev. 2.00, 09/03, page 599 of 890